Tubing construction



- R. H. BROWNLEE. TUBING CONSTRUCTION. 'l APPLICATION FlLED SEPT-22, |919.

yPmented Jan. 27,1920.

2 SHEETS-SHEET 2.

ROY H. BROWNLEE, 0F PITTSBURGH, PENNSYLVANIA.

TUBING CONSTRUCTION.

Specification of Letters Patent.

Patented J an. 27, 1920.`

Application ledseptember 22, 1919. Serial No. 325,436.

To all whom it may concern.'

Be it known that I, Roy H. BROWNLEE, a citizen of the United States,` and resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new -and useful Improvement in Tubing Constructions, of which the following is a speciiication.

This invention relates to a tubing construction for use in tubular oil stills, water tube boilers, and for any other purpose of the same general nature in which a metallic tubular structure contains vaporizable matter and is subjected to relatively high temperatures and pressures.

One object of the invention is to provide a metallic tubing construction so arranged that access to all lengths of the tubing ernployed in an installation may be had from the exterior of the furnace, and a cleaning tool readily run through each length of'tubing. Another object of the invention is to provide a tubing structure which furnishes a continuous and jointless path for the hot vapors therein, and in which the joints are located exteriorly'of the furnace so that they are readily accessible and are not subjected to high temperature' and hot vapors. A further objectof the invention is to provide a construction in which the tubes'employed are so cut, matched, and welded that an integral structure with smooth land iirm connections is provided.

In the accompanying drawings, Figure 1 is a diagrammatic vertical-section through a furnace showing a tubing system embodying the construction of the present invention in position therein; Fig. f2 is a diagrammatic rear elevation of the furnace; Fig. '3 is an elevation of a connection between two adjacent heating tubes land their connecting tube; Fig. 4 is an end view ofthe connecting tube showing the heating tubes joined thereto; Fig. 5 is a section through the connecting tube onthe line 5 5 Fig. 3; Fig. 6 is an elevation of that portion of one of the heating tubes which is adjacent `the point of connection; Fig. 7 isa view similarto that of Fig. 3 but illustrating a modified cutting of the tubes; Fig. 8 is Ian end view of the connecting tube and heating tubes of the modified construction; Fig. 9 is an elevation ofv one of the heating tubes of this construction, and Fig. 10 is a cross section on the line 10-10 Fig. 7. v

In the drawings, 1 is a continuoustubing structure set in a furnace 2, and arranged to extend vertically a considerable proportion of the height of the furnace. This tubular structure or tubing system 41 comprises a plurality of relatively long sections 3, which are arranged to be exposed to heat in the furnace, and Awhich are inclined to the vertical and joined to form a continuous circuitous lengthof tubing; and shorter sections 4 of greater diameter than the sections 3 and to which the latter are welded. The ends of adjacent tubes 3 are connected with each other and with the exterior. of the furnace by means of their mutual connecting tube or section 4. Each section 4 is arranged to extend beyond the outer face of the furnace wall and is closed at its outer extremity by means of a packing flange 5, which may be of any usual form. In order to form a smooth joint `with th heating tubes 3v which connect withit, and to permit a cleaning tool to be more readily passed through it and into either of the heating tubes, the connecting tube 4 is'made of a slightly greater diameter than the heating tubes. At its inner extremity, as shown in Figs. 3 and 5, the tube 4 is flattened out from a tube of circular cross section into one of a generally ellipticalsection of such dimensions that its shorter" axis is equal to.

the diameter of theheating tubes 3.

The inner end of the tube 4 is also cut away in two angular directions from approximately its lmedian line to form two equal edges or faces 6, as is shown in Figs. 3 and 5. Each of the tubes 3 to be joined thereto is preferably bent so as to provide a portion 7 curving toward `the connecting tube. This is in order that thev tubes 3 may be more rapidly matched lwith the end of the connecting tube 4, and also in order that vapors passing through the tubes will not be directed into andalong the connecting tube. At the extremity of such curved portions, each of the tubes is cut away as at 8 in Figs. 3 and 6, to match the cut edges 6 of the connectin tube. It will be seen that the angle at whic the ends of the tubes 3 must be cut will depend upon the degree of curvature of the portions 7, the angle at which they approach the tube 4, and the angle at which the tube 4 is cut. When so desired, certain of the/adjacentheating tubes ma vbe arranged parallel to each otherand t eir adjustment to the`end of their connecting tubes made bythe curvature of their end portions and the angle at which they and the connectingtubes are cut. Y

In making the tube construction, the heating tubes and the connecting tube are cut into the forms above described by any convenient means. Preferably, such cutting 1s performed by means of a welding and cutting torch using a suitable cutting gas. The

tubes are then brought together .into the position shown in Fig. 3and the joints are welded by the use of the welding torch and a thin welding rod. In the welding operation, this welding rod is passed along the lines of division between the tube sections while the ame of the torch is being applied thereto, so that such linesy of division are covered with a smooth coating of metal from the rod and a firm and smooth welded connection made.

In the form of the construction having a modified matching of the tubes, as illustrated in Figs. 7 to 10 of the drawings, the inner portion of the connecting tube 4 1s flattened, as in the previously ydescribed form, into van elliptical section the shorter axis of which is equal to the diameter of theheating tubes 3. The end or edge of the tube is, however, normal to the longitudinal axis of the tube instead of being cut away on planes at an angle thereto. Both legs of heating tubing 3 are, in this form also, bent to form curved portions 7 adjacent their extremities. Instead however, of being cut in one direction, asin the other form, it is necessary that they b e cut twice in order that they may match with each other and with the connecting tube. They are, therefore, cut along the lines 9 and 10, both cuts being at an angle to the longitudinal axis of the tube and meeting at the point 11.

In matching the tubes for welding, the edges 10 of the tubes 3 are brought into conv tact with each other and the edges 9 are brought into contact with the edge of they tube 4, as is shown in Fig. 7. In making the weld, the process is in general similar v'to that previously described. It will be noted, however, that the line 10,

alongwhich the tubes 3 are cut and along which they are in contact with each other, is not, even at its deepestv point, .equal to the diameter of the tubes. It is necessary, therefore, that metal be supplied from the welding rod to bridge over the space thus left open inthe face of the tube 4. This filled l space is indicated at 12 in Figs. 8 and 10 of the drawings. The-connection-thus formed, while not so smooth as that formed in the manner illustrated in Figs. 3 to 6 inclusive, iyet relatively so, and is strong and servicea e.

The construction above described provides a neat and strong welded connection between two lengths of tubing set at an angle to each other, and a third tubular section set at such -structure when installed in a furnace reduces possible leakage to a minimum, since the path of the 'vapors through the tubing is such that a large volume of hot vapors cannot come directly into contact with the packing ange 5. This feature is of particular importance when 7the construction is used 'to forma tubular oil still, as oil vapors,

when heated to a high temperature, are destructive to packing and are particularly liable to leak through joints against which a stream of such vapors impinges directly. The ange 5 is protected from the heat of the furnace, and from the heated vapors by the length of the .tube 4, this length being as reat as is advantageous in the particulariuse for which the construction is installed. The flange is also protected from the hot vapors by the fact that the curved portions 7 of the heating tubes so direct the stream of vapors that only a small proportion of such stream-penetrates any appreciable distance into the tube 4.

To clean the heating tubes, the flanges 5 are removed, and a suitable cleaning tool, such as anair operated tube cleaner, passed through the connecting tubes 4 into the tube 3. This cleaner with its flexible connection may be inserted into either of the heating tubes to which each tube 4 is welded and can be easily passed through the tube. Each tube may also be cleaned lfrom either end, or from both ends successively. This accessibility for cleaning is also of particular importance where the construction is used as a tubular oil still, asit permits frequent removal of carbon from the tubes without requiring the furnace to be cooled priorto the 'heating tubes, adjacent tubes being set at an angle .to each other; and metallic connecting tubes of greater diameter than the heating tubes arranged to project beyond the furnace wall and'to the inner end of each Lacasse:

y of which `the adjacent heating tubes are so tube extending through the wall of said furnace, and a pair of heating. tubes disposed at an'angle to said horizontally disposed tube and welded to the inner extremity thereof.

3. In a tubing construction a furnace', a

tube -extending substantially horizontally through saidjurnace wall, and a'pair of heating tubes disposed at an angle of less than forty-five degrees to said horizontally disposed tube and welded thereto.

4.-. A metallic tubing construction comprising a connecting tube of regular cross section, and a pair of vheating tubes Iset at an angle to each other and cut away at their extremities on planes at an angle to the longitudinal axis of the tubes and welded to oneend of said connecting tube. t

5. A metallic tubing construction comprising a connecting tube, and a -pair of heating tubes curved toward each other adjacent their connected extremities and having such extremities cut away on planes at an angle to the longitudinal axis of the tubes and welded to one end of said connecting tube; said connecting tubebeing of greater diameter than the heating tubesand fiattened adjacent its connecting extremity'to a regular cross section havingits shorter axis equal to the diameter of the heating tubes.

6. A metallic tubing construction comprising a connecting tubeof regular Across section, and a pair of heating tubes curved toward each other adjacent their extremlties and having theirv extremities cut away on planes atan angle tothe longitudinal axis of the tubes and welded to one end ofsaid connecting tube.

7. A metallic tubing construction comprising a` connecting tube, and a pair of heating tu es having their extremities cutaway on planes at an angle to the longitudinal axis of the tubes and welded to one end of said connectlng tube; said connecting tube being of greater diameter than the heating tubes and flattened adjacent its connecting extremity to a regular cross section having its shorter axis equal to the diameter-of the heating tubes.

l 8. A welded tubing construction comprising a pair of heating tubes set at an angle to each other,` and a connecting tube of greater diameter than said heating tubes and iattened adjacent one extremity to a regular cross section having' its shorter axis equal to the diameter `of the heating tubes; said heating tubes being each cut away adjacent their connecting extremities on two planes at an angle to the longitudinal-axis of the tubes to match withand be welded to each other and the flattened end of the connecting tube. I `1 9. A metallic tubing construction comprising a connecting tube of regular cross section, and a pair of heating tubes set at an angle to each other and curved toward each other adjacent their extremities; said heating tubes having their extremities out away on planes at anjangle to the longitudinal axis of the tubes andwelded to one end of said connecting tube.

10. A welded tubing construction comprising a pair of heating tubes set at an angle to each other and curved toward each other adjacent their extremities, and a connect-` hand.

v ROY H. BROWNLEE. Witnesses:

R. H. Umnmfiila` GRETTA W. ALs'roN. 

